Although controversial, foods have been clinically reported to provoke a wide spectrum of psychological and behavioral reactions in susceptible individuals. Results from controlled research have been conflicting, with studies focusing on the effect of food colors on hyperactive children, the role of wheat in schizophrenia, and the association between sugar consumption and behavior in children. Common flaws in these studies are the use of small samples (low statistical power) and the failure to preselect for sensitivity to the substance being investigated. The central goal of our proposed research program is to test whether foods can provoke psychological or behavioral responses in selected individuals under double-blind conditions. In order to accomplish this goal, we propose to develop and test a method of blinding meal-sized portions of foods in a placebo base. When this has been successfully completed, a second study will be conducted in two phases: (1) a double-blind screening for food sensitivity phase, in which potential subjects must demonstrate sensitivity to a food before admission to the second phase; and (2) for those passing the screening phase, a double-blind experimental phase. This will consist of admission as in-patients with subsequent double-blind oral challenges of either food or placebo with psychological behavioral, and heart rate data collected. The oral challenges will be given in a randomized, counterbalanced, cross-over design with one "active" and one placebo per patient. Results of this study will be of relevance to allergy, psychiatry, nutrition and psychology.